During this period, the collaborative team focused on the SAR study and the hit-to-lead development of a top series from the previous qHTS. The team has gained valuable structure activity relationship information from the synthesized analogs and used it to design more potent analogs. Top analogs are far more potent than the original hit, active in ex-vivo studies, and have good permeability and minimal efflux liability. Target engagement probes based on a different chemotypes have also been synthesized and are being evaluated in target-identification studies.